Kalkulator Petua 72
Anggar berapa tahun wang anda menjadi dua kali ganda pada kadar faedah tertentu.
Berjalan dalam pelayar anda. Fail anda tidak pernah meninggalkan peranti. Lihat cara menyemaknya
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Cara melakukannya
- 1Isi ruang
Taip nombor anda atau pilih pilihan yang diperlukan.
- 2Lihat hasil
Jawapan dikemas kini serta-merta apabila anda menukar nilai.
- 3Gunakan
Salin hasil atau catatkannya. Tiada apa dihantar ke mana-mana.
About this tool
Enter an annual rate of return. The rule of 72 divides 72 by the rate to estimate the years to double. The tool also shows the exact result, and the rule of 114 and 144 for tripling and quadrupling.
The rule
Divide 72 by the interest rate to get the approximate years for money to double with compound interest. At 6 percent it takes about 12 years, at 9 percent about 8 years. It is accurate for rates between about 4 and 12 percent.
Why it matters
It shows how rates and time compound. It also works for inflation: at 3 percent inflation prices double in about 24 years.
Other versions
Use 114 for tripling and 144 for quadrupling. For very high or low rates, the exact formula is shown for comparison.
Contoh berselesaian
With the boxes at their starting values (Annual rate of return (%): 7), the tool shows: Years to double (exact): 10.2; Years to triple (rule of 114): 16.3; Years to quadruple (rule of 144): 20.6; Years to double (rule of 72): 10.3. Change any box to see your own numbers. The result updates as you type, and nothing leaves your browser.
Petua untuk hasil terbaik
Semak setiap ruang sebelum mempercayai hasil, kerana satu angka yang salah mengubah keseluruhan jawapan. Gunakan nombor tepat daripada slip gaji, bil, sijil atau kontrak dan catat tarikh anda mengira. Kadar, ambang dan peraturan berubah dari semasa ke semasa, jadi untuk cukai, yuran dan perkara undang-undang, anggap hasil sebagai anggaran dan sahkannya dengan sumber rasmi yang dinyatakan pada halaman ini. Anda boleh mencuba sebanyak mana senario; tiada apa disimpan atau dihantar dan memuat semula halaman mengosongkan ruang.
Ringkasnya
Soalan lazim
Is it exact?
No, it is an approximation. The exact figure uses logarithms and is shown below the estimate.
Does it work for inflation?
Yes. Divide 72 by the inflation rate to see when prices double.
Why 72?
72 has many divisors and gives a good fit to the exact formula at typical rates.
Does it include contributions?
No. It assumes a single amount that compounds.